The present invention relates to steelmaking furnaces, particularly electric arc steelmaking furnaces which are mounted for tilting. More particularly, the invention relates to means for tapping such furnace exterior to the furnace, and is especially advantageous when utilizing continuous feeding.
Schnitzer et al. U.S. Pat. No. 4,523,747 teaches a method and apparatus for tapping a smelting furnace, generally of the electro-plasma type. This patent shows that the furnace walls extend outwardly from the furnace beneath the watercooled walls to form a generally trapezoidal region having a common bottom with the main portion of the furnace. In addition, this patent has a vertical discharge nozzle when the furnace is not tilted and an inclined nozzle when the furnace is tilted, which results in a ragged pouring stream and excessive wear of the nozzle refractory. The reference also provides a ferrostatic head above the pouring nozzle at all times during the refining period. Because of the presence of this ferrostatic head above the pouring nozzle when the bath is totally molten, failure of nozzle shut-off devices have resulted in several accidents at furnaces equipped with such arrangements.